Selector



D. L. LIENZEN Oct. 6, 1931.

SELECTOR s sheets-Saut 2 Filed Feb. 12, 1930 3 Sheets-Smet 3 o. L. :.sNzajN sumaron med Feb'. 12. 1930 K a s aAw.

s e'a v Oct. 6, 1931.

Patented Oct. 6, 1931 UNITED STATES PATENT OFFICE DAVID lI/AUREUSTLIUSV LIENZN, OF STOCKHOLM, SWEDEN, ASSIGNOR TO TELEFON- AKTEBOLAGET L. M. ERCSSGN, OF STGCKHOLIVL,V SW'EDEN, A COMPANY 0F SWEDEN SELECTOR Application led February 12, 1930, Serial No'. 427,849, and in Sweden October 23, 1929.

The present invention relates to selectors used in automatic telephone systems and more particularly to selectors of the kind, the contact fields of which consist of mu- 'tually parallelbare wires or the like comlmon to a group of selectors, and which are provided with a longitudinally displaceable Contact arm adapted to move into the contact lied between its wires to select the wanted line, a number of contact springs or wipers disposed on the contact arm then making Contact with the Wires of the contact field, Selectors of' this kind should be so constructed as to prevent contacts between the test wiper and the talking line wires of the cont-act field during the setting of the selector, as the test wiper must generally be kept alive during the setting of the selector, at least in selectors having searching motion,

and therefore might cause disturbances in existing talking connections.

taining to the talking line branches have for this purpose been disposed on the one side of the path of' motionof the contact arm whereas wires appertaining to the third conductors, the so called test wires, have been disposed on the opposite side of said path. ln practice, this disposition has, however, the disadvantage that the space occupied by the contact field can not beentirely utilized as the wire row on the one side of the path off the Contact arml will accommodate only half' many Wires as that on the opposite side. The present invention has for its object to render possible a better utilizationv of the space in the Contact field and consists substantially in certain dispositions of the wires in thc contact field in combination with 40 means to prevent the test wiper from making Contact with the talking line wires during the settingv operation.

The invention will be more closely described with reference to the accompanying drawings. Figures l, 2 and 3 show diagrammatically an embodiment of the invention, the Contact arm taking up three different contact positions. Figures 4, 5 and 6 show in similar manner another embodiment and i; Figures 7, 8 and 9 a third embodiment;

In hitherto known selectors of this kind the wires apper- In the embodiment shown in Figures l, 2 and 3 the wires belonging to a line group or a contact row respectively in the Contact field are distributed on both sides of the path of the Contact arm 1 as indicated by the letters g of reference a, b, c whereof a and Z) designate those wires to which both branches of the talking line are connected whereas c designates that wire to which the test wire is connected. Apparently all the wires c, b, c appertaining to one and the same line are disposed behind each other in the same wire row and on the same side of the path of the contact arm. The wires are in known manner common to a plurality of selectors disposed ff above each other and extend in a manner known per se through holes in insulating plates 2 which are spaced apart by suitable distances so as to ensure a sufficient rigidity of the wires.

The connection between the line 3 terminating in the selector and the lines connected to the contact field takes place by means of two groups of contact springs or wipers 4, 5, 6

and 7, 8, 9 respectively which are disposed in a cavity l() in the front end of' the contact arm in such a manner that the contact springs 4, 5, 6 are adapted to make contact with the wires disposed on the lef't hand side of the path of the Contact arm, whereas the contact springs 7, 8, 9 are adapted to make contact with the wires disposed on the right hand side of said path. The different contact springsV are two and two electrically connected to each other and to the talking line wires a, I) and the test Wire c appertaining to the incoming line 3. The wire rows disposed on opposite sides of the path are displaced in relation to each other in such a manner that during the motion of the contact arm into the contact field connection is established alternately to lines disposed on opposite sides of the path. The same result may, of course, be obtained by a displacement of the groups of contact springs 4, 5, 6 and 7 8, 9 in relation to each other whereas the wires c, b, c in the two rows are disposed rightly opposite each other.

The setting of the contact arm l may take place in any known manner. On the drawings only one arrangement for the longitudinal displacement of the contact arm is shown consisting' of a toothed wheel 12 disposed on a shaft 11 and a toothed rack 13 rigidly connected to the contact arm 1, said shaft 11 being, by way of example, adapted to be connected to a continuously rotating shatt by means of a magnetic clutch. The contact arm is adapted to be locked in each set position by means of a locking magnet the armature 15 of which is provided with a detent 16 adapted to engage slots 17 in a bar 1.8 rigidly connected to the arm 1 so as to centre tlie wiper exactly in each contact position.

lf the selector is provided with a plurality of line groups and contact rows respectively the contact arm 1 must be adapted to be set in two directions in the same plane in such a manner that it initially mores oi the contact field to select a line group or contact row respectivelyT and thereupon into the contact field between the wires in said row to select the wanted line. During the first motion the contact arm may in known manner either perform a parallel motion perpendicularly to the arm or rotating motion the contact arm then turning about an airis parallel with the wires in the field. ln the former the contact rows are mutually parallel while, in the latter case. are disposed radially in relation to the ze, s ot rotation of the arm in such a manner that the arm during its motion into the contact field performs a motion in radal direction. rlhe motion mechanisms required therefore may be of any known kind and need not be more closely described in this connection as they are of no importance for the invention.

In its normal starting position the contact arm in its entirety extends outside the `t'ront end of the wire row. During the motion o'l the contact arm into the Contact field the two talking branches a and of the incoming line 3 are disconnected from the appertaining contact springs 5, 6, 8, 9 provided in an apparatus not disclosed here and appertaining to the selector, by way of exemple a sequence switch or a. relay, so that said contact springs are dead, i. e. disconnected from the current source, during the motion. Said contact springs may thus make contact during the motion ot the contact arm with the different wires in the field without thereby causin any disturbances. To prevent that the test ers 4 and 7 during the setting motion cause disturbances by making contact with the wires o, 7) the selector is, accordingy to the invention, provided with a switching device which in the shown example consists ot two contact springs 19, Q0, whereof the spring 19 is adapted to be actuated through the intermedium of a flexible arm 21 which by means of a wheel Q2 disposed thereon is in elastic engagement with the bar 18 so as to be actuated by teeth 23 disposed on the bar 18 during the motion of the contact arm into the coriact field, The latter teeth are so adjusted that the contact between the springs 19, 20 is interrupted when the test wipers 4, 7 pass over the talking line wires a, l). Said switching device is included in the testing circuit of the line 3 in such a manner that the test wipers 4, 7 are tensionless or dead when they pass the wires a and b. In the testing circuit of the line 3 a testing relay 24 may be included in usual manner which relay, when the selector operates as nder, in known manner brings the selector to stop as soon as the latter iind a free line.

Figure 1 shows the contact arm in its first setting position the contact springs 4, 5, 6 then making contact with the first line a, b, c in the lett hand wire row. Figure 3 shows the contact arm in its second setting position, the contact springs 7, 8, 9 then making contact with the lirst line a, b, c in the right hand wire row which line the second line in the line group in question. Figure 2 shows an intermediate position, which is passed by the contact arm during its motion from the first to the second position. ln this intermediate position the test wiper 4 makes contact with the wire o appertaining to the first line in the line group but said contact may not cause any disturbance because the Contact between the contact springs 19, 20 is now interrupted as the elastic arm Q1 in this position is actuated by a tooth 23. The teeth 23 may, of course, be ot such a nature that the contact 19, 2O is interrupted during the entire period of contact between the test wiper and the wire On account of said displacement between the wires in the two wire rows the Contact springs 7, 8, 9 do not make contact with the wires a, c on the right hand side in said intermediate position. Then the contact arm reaches the position shown in Figure 3 the Contact springs 4, 6 take up such a position that they do not make contact with any wires on the left hand side. Innnediately before the contact arm reaches the exact setting position the Contact 19, 2() is closed, a testing of the line then taking place just a moment before the arm takes up the exact contact position. It the selector operates as finder and the second line should be engaged the contact arm will continue its motion until it reaches a free line the testing relay 24 then operating and bringing the selector to stop. Then the locking magnet 14 becomes cle-energized so that the detent 16 is released and locks the arm in an exactly centered poition. On account ot said mutual displacement between the two wire rows the Contact arm wi l thus alternately establish communication with lines disposed on opposite sides of the path of the contact arm.

The described arrangement renders possible a complete utilization of the space occupied by the contact fields so that both wire rows will contain the same number of equidistant wires. As .a consequence, a larger num-ber of lines ymay be connected up within the same space o the Contact field than has hitherto .been possible.

The embodiment shown in Figures 4, 5 and 6 is differentiated from the one just described substantially in that the 'wires a, b, c appertaining to the same line are mutually grouped 4in another manner which. in turn rende-rs possible a reduction `in the number ot contact springs in the contact arm. In this embodiment the Yarm is thus only provided with four contact springs 25, 26, 27, 28. The ygrouping of lthe wires a, b, c may be seen from the dashed and dotted lines 29, 30, which are drawn in such a manner that they separate the wires Kbelonging to adjacent lines :from each other. As is `clearly understood from the drawings the talking wires a and Z) appertaining to the first line are Vdisposed in the right hand Wire row whereas the appertaining c-wire is disposed in the left hand wire row. On the other hand, the second l-ine has its speaking wire a, b in the left hand wire row whereas the test wire -c is disposed in the right hand row. In the third line the wires are disposed in similar manner as in the first line and `in the fourth krline they are disposed in similar manner as in the second etc. The arrangement may in certain cases be so carried out that, by way of example, the wires a and c ineach individual line cha-nge places. As the mutual position ofthe kwires appertaining rto each individu-al l-ine is altered when passing from one setting position to another it is clearly understood that a corresponding -shifting of the contact springs 25, 26, 27, 28 must take place lduring the setting besides which one lof the contact springs must then be disconnected in each special setting position. This shifting is brought about ac'iording to the invention by a switching `device simi-lar to lthat shown in Figures 1 to The switching device is in. this case constituted by a plurality of contact springs 31 to 40, whereof the contact springs 33, 34,139, 40 control the connecting up of the test wire belonging to the incoming line 3 in such a manner that the contact springs 25 and 28 ralternately serve as test wipers. The operation is clearly under- `stood upon a comparison between the Figures 4, 5 and y6 showing -three Adifferent positions ot the contact arm. In Figure 4, the arm is shown in its first contact position, the contact springs 27,28 and 25 then making contact `with the corresponding wires a, 7), c appertaining to the first line. The contact spring 27 is connected to the a-wire of the incoming line over the Contact springs 36, 37 the contact spring 28 .is connected to the -wire of the incoming line over the contact springs 38 and 39 and the contact spring 25 is vconnected .to the /c-wire of the incoming line over the contact springs 33 and 34. The contact spring 26 which is directly connected to the contact spring 32 in the switching device is in .this position entirely disconnected. The springs 31 to 40 are adapted to beactuated in such .a manner that three different switching operations may -tale place. For this purpose the bar. 18 is provided with teeth 41, 42 of different heights, so that the elastic arm 21 during i the motion of the contact arm is successively brought to take up three different positions, i. e. a bottom position in the bottom of the toothed space, an intermediate position on a tooth 41, and finally a top position on the tooth 42. Figures 4, 5 and 6 show three consecutive positions of the contact arm. cor responding -to said three Adifferent positions of the switchingdevice. The position shown in Figure 4 corresponds to the first setting position. The position shown in Figure 5 corresponds to the second setting position. Figure 6 shows an intermediate position of thecontact arm between the second and third settling positions. As is understood by the figures, the step between two consecutive contact positions will vary in such a manner that the step between .the secondand third setting positions is twice as great as the step between lthe first and second setting position. In similar manner the step between the fourth and fifth setting positions is twice the step between the third and fourth setting positions etc. Every second setting step will thus be twice as long as the next preceding one.

Then the contact arm moves from the first to the second setting position a shift-ing of the Contact springs 25 to 28 takes place so that the contact spring 25 which previously was connected to the c-wire now is connected to the b-wire whereas the contact spring 26 which previously was entirely disconnected now is connected to the a-wire. Instead the Contact spring 27 is now entirely disconnected whereas the contact spring 28 which previously was connected to the b-wire now is connected to the c-wire. When the contact arm has moved forward a further step equal to the distance 1cetween the first and the seco-nd setting positions the contact springs 25 to 28 take up the intermediate position shown in Figure 6 in which all the Contact springs are entirely disconnected trom the incoming line 3 as the elastic arm 21 now bears against the lower tooth 41 the switching device now taking up an intermediate position in which all the contact vsprings 31 to 40 are separated from each other. 1n this position no locking of thc contact arm may talco place because the bar 18 is not provided with any cerrespomling recess for the detent 16. The contact arm continues thus its motion `until it reac ies the next setting position wherein the contact springs 25, 27, 28 make contact with the wires c` c and o of the line connected up in this position, whereas the contact spring Q6 is entirely disconnected. The switching device is then actuated by a tooth and consequently it takes up the same position as in Figure el.

The shown embodiment having four contact springs may, as is readily understood, also be applied in systems having quad lines, all talking line wires being then preferably disposed in one wire row and the third and fourth wires in the other wire row.

Evidently the switching device may be carried out in many different manners and it may be adapted to be actuated by any movable part of the selector mechanism which is positively connected to the contact arm.

Figures S and 9 show a modification of the embodiment according to Figures 1, 2 and 3, the shifting ot' the test wipers 4, 7 boing here brought about by means of a switching de 'ice co-operating with the wires in the contact field. Each test wiper 4 and T is thus provided with a wheel 43 and 44 respectively of insulating material rotatably Liosed thereon and provided with a metallic portion 45 and 46 respectively which is in conductive communication with the contact spring 4 and 7 respectively. Said wheel is at its circumference provided with three recesses 4T adapt-ed to engage the wires a, Z, c in such a manner that the wheel during the motion of the contact arm is brought to rotate while maintaining a positive tooth engagement with the wires. The arrangement is then carried out in such a manner that the metallic portion 45 and 46 respectively only may make contact with the cwircs but on the other hand not with the cand /-wircs. Figure .7 shows the contact arm in third setting position, the contact springs T, 8, 9 then making contact with the corresponding wires o, o, c in the right hand wire row whereas the springs 4, 5, 6 in similar manner as in Figure $3 take up an intermediate position between the different wires in the left hand wire row. Figure 9 shows the contact arm in the next settiner position the communication being then instead established over the contact springs 4, 5, G whereas the contact springs i', S. 9 take up an intermediate inoperative position. Figure 8 mows a contact arm in a posit-ion between the third and fourth setting positions and illustrates the test wipers 4, 7 being entirely d.s -oniiected in this position. It is also seen from the drawings that the testing contact z-'ilirings may not in any position between two adjacent setting positions establish unwanted contacts with the talking line wires a and Z).

n the embodiments according to Figures 1 to 3 and 7 to 9 the sets of contactsprings disposed on opposite sides of the contact arm need not necessarily be connected in parallel but may be adapted to be connected alternately in consecutive setting positions of the contact arm to the incoming line 3, for instance by means of a switching device mechanically dependent upon the motion mechanism of the selector and of a. similar kind as that shown in Figures 4 to G.

In case two complete sets of contact springs each comprising three contact springs are used the arrangement may also be so carried out that both sets of contact springs in each individual setting position make contact each with one line in the contact field the incoming line 3 being adapted to be alternately connected to the one or the other of the two sets of contact springs by means of a relay or other switching device.

I claim:

l. A selector arrangement comprising a number of selectors, a Contact iicld consisting of parallel bare conductors and common to a plurality of selectors, a longitudinally displaceable contact arm on each selector', means to move said contact arm into the contact field between the bare conductors thereof to select any of the lines connected to the contact field. the test conductors of said lines being equally distributed on both sides of the path of the contact arm and equally spaced on each side.

2. A selector as claimed in claim 1, characterized in thatl the test conductors are disposed on the same side ofthe path of the con` tact arm as the appertaining talking line conductors.

A selector arrangement comprising a number of selectors, a contact field consisting of parallel bare conductors and common to a plurality of selectors, a longitudinally displaceable contact arm on each selector, means to move said contact arm into the cont-act field between the bare conductors thereof to select any of the lines connected to the contact field the two talking line conductors bclonging to each of said lines being disposed on the one side and the third conductor on the other side of the path of the contact arm, the mutually corresponding conductors of consecutive lines being alternately disposed on opposite sides of the path.

4. A selector arrangement comprising a number of selectors, a contact field consistinj.` of parallel bare conductors and common to a plurality of selectors. a longitudinally displaceable contact arm on each selector, means to move said contact arm into the contact iield between the bare conductors thereof to select any of the lines connected to the contact field said lines being adapted to be alternately connected in consecutivo setting positions to line conductors on opposite sides of the path of the contact arm.

A selector arrangement comprising a number of selectors, a contact lield consisting TLS-25,911

of parallel bare conductors and common to a plurality of selectors, a longitudinally displa ceable contact arm on each selector, means to move said contact arm into the contact field between the bare conductors thereof to select any of the lines connected to the contact field said lines being adapted to be alternately connected in consecutive setting positions to line conductors on opposite sides of the path of the contact` arm, two sets of contact springs disposed on opposite sides of said contact arm, said two sets of contact springs being mutually displaced in such a manner, that the connections in consecutive setting positions are alternately established over the one and the other of two sets of contact springs.

(l. A selector arrangement comprising a number of selectors, a contact field consisting of parallel bare conductors and common to a ,lniality of selectors, a longitudinally displaceable contact arm on each selector, means to move said contact arm into the contact field between the bare conductors thereof to select any of the lines connected to the contact field said lines being adapted to be alternately connected in consecutive setting positions to line conductors on opposite sides of the path of the contact arm, two sets of contact springs disposed on opposite sides of said .ontact arm, the line conductors being niutually displaced in such a manner that the connections in consecutive setting positions are alternately established over the one and the other of the two sets of contact springs.

7. A selector arrangement comprising a number of selectors, a contact field consisting of parallel bare conductors and common to a plurality of selectors, a longitudinally displaceable contact arm on each selector, mea to move said contact arm into the contact field between the bare conductors thereof to select any of the lines connected to the contact field said lines being adapted to be alternately connected in consecutive setting 7positions to line conductors on opposite sides of the path of the contact arm, an electric switching device adapted to be mechanically controlled by the motion mechanism of the sclector, whereby the incoming line during the setting motion is alternately connected to the one and the other of two sets of contact springs disposed on opposite sides of the contact arm.

8. A selector arrangement comprising a number of selectors, a contact field consisting of parallel bare conductors and common to a plurality of selectors, a longitudinally displaceable contact arm on each selector, means to move said contact arm into the contact field between the bare conductors thereof to select any of the lines connected to the contact field said lines being adapted to be alternately connect-ed in consecutive setting positions to line conductors on opposite sides of the .1 path of the Contact arm, a line terminating in the selector, the wires of said line being connectedto contact springs disposed on the contact arm over `an electric switching device which is adapted to be mechanically controlled 4by the motion mechanism of the selector in such a manner that the connections between the incoming 'line and the Contact springs may be interrupted and shifted as required during the setting of the contact arm.

9. A selector arrangement comprising a number of selectors, a contact field consisting of parallel bare conductors and common to a plurality of selectors, arlongitudinally displaceahle Contact arm on each selector, means to move said contact arm into the contact field between the bare conductors thereof to select any of the lines connected to the contact field eid Ilines being adapted to be alternately connected in consecutive setting positions to line conductors on opposite sides of the path of the contact arm, two sets of contact springs disposed on opposite sides of said contact arm, said two sets of contact springs being mutually displaced in such a manner that the connections in consecutive setting positions are alternately established over the one and the other of two sets of contact springs, a line terminating in the selector, the wires of said `ine being connected to contact springs disposed on the contact arm over an electric switching device which is adapted to be n'ieclianically controlled by the motion mechanism of the selector in such a manner that the connections between the incoming line and the contact springs may be interrupted and shifted as required during the setting of thefeontact arm.

l0. A selector arrangement comprising a number of selectors, a contact field consisting of 1 aral'lel bare conductors and common to a plurality yof selectors, a longitudinally displaceable contact arm on each selector, means to move said contact arm into the contact field between the bare conductors thereof to select any of tl e lines connected to the contact field said lines being adapted to be alternately connected in consecutive setting positions to line conductors on opposite sides of the path of the contact arm, two sets of contact springs disposed on opposite sides of said contact arm, the line conductors being mutually displaced in snch a manner that the connections in consecutive setting positions are alternately established over the one and the other of the two sets of contact springs, a line terminating in the selector, the wires of said line being connected to Contact springs disposed on the contact arm over an electric switchincr device which is adapted to be mechanically controlled by the motion mechanism of the selector in such a manner that the connections between the incoming line and the contact springs may be interrupted and shifted as re'- quired during the setting of the contact arm.

1l. A selector arrangement comprising a number of selectors7 a contact field consisting of parallel bare conductors and common to a plurality of selectors, a longitudinally displaceable contact arm on each selector, means to more said contact arm into the contact field between the bare conductors thereof to select any of the lines connected to the contact field said lines being adapted to be alternately connected in consecutive setting posi- L?, tions to line conductors on opposite sides of the path of the contact arm, an electric switching device adapted to be mechanically controlled by the motion mechanism of the selector, whereby the incoming line during 1 the setting motion is alternately connected to the one and the other of two sets of contact springs disposed on opposite sides of the contact arm, a line terminating in the selector, the wires of said line being connected to con- 2.5, tactsprings disposed on the contact arm over an electric switching device which is adapted to be mechanically controlled by the motion mechanism of the selector in such a manner that the connections between the incoming line and the contact springs may be interrupted and shifted as required during the setting of the contact arm.

l2. A selector arrangement comprising a number of selectors, a contact field consisting 3a of parallel bare conductors and common to a plurality of selectors, a longitudinally displaceable contact arm on each selector, means to more said contact arm into the contact field between the bare conductors thereof to select 35 ny of 'the lines connected to the contact field saidL lines being adapted to be alternately connected in consecutive setting positions to the line conductors on opposite sides of the path of the cont ct arm, a line terminating in the 4o selector, the wires of said line being connect ed to contact springs disposed on the contact arm over an electric switching device mechanically cooperating with the conductors of the contact lield by means of which device 45 the connection of the contact springs may be shifted as required.

In testimony whereof I alix my signature.

DAVID LAURENTIUS LIENZN. 

